1986 Mercury 150 Black Max Carb Leak

timo14

Cadet
Joined
Jun 30, 2005
Messages
11
1986 Mercury 150 Black Max. Fuel is leaking out of the front of my carbs (all 3 of them) when the motor is tilted up. I did not notice it until I installed a new fuel filter (external with water separator) and primer bulb. When I pumped the ball it had a lot of air in it, so i pumped it alot. I first thought i flooded the engine. But it started right up. It runs great otherwise. I have read in other posts that i shoud keep some rags handy & not worry about the leak. Seems a little fishy though.<br />Thanks in advance for any help.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,319
Re: 1986 Mercury 150 Black Max Carb Leak

I rebuilt all 6 carbs and mine still does it. It's the nature of the beast I guess.
 

heybaylor

Petty Officer 2nd Class
Joined
Jan 17, 2005
Messages
187
Re: 1986 Mercury 150 Black Max Carb Leak

if you tilt it all the way up ..yep it spills the gas out of the bowl vent ..something about gravity..<br />But , mercury has installed a "suckit " valve in the lower corner of the silencer ( airbox) <br />when it spills into the box , the next time you start it, it pull's the mess into the intake manifold ...<br />Tip" keep your airbox wiped out every once in a while to get rid of the dirt/dust that settles in there ...<br />dirt will be sucked in , and worst case , clog the valve ..and the mess runs out ..<br />especially if your gasket ( airbox) is missing and or bad seal.<br />my 86 XR2 stays pretty clean ..with a little maintenance.. and I seldom have a reason to tilt it all the way up ..about 45 degrees is plenty ..<br />hope this helps ..
 
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